Electron relay apparatus



March 7, 1939. BROWN 2,149,387

ELECTRON RELAY APPARATUS Filed May 20, 1956 3 Sheets-Sheet 1 INVENTOR. [/me'r A. 5/"0/407 BYQ A T TORNEY March '7, 1939. E. L. BROWN 2,149,387

ELECTRON RELAY APPARATUS Filed May 20, 1956 3 Sheets-Sheet 2 IN VEN TOR. f/mer Z. 5/0W/7 A TTORNEY March 7, 1939.' E, BROWN 2,149,387

ELECTRON RELAY APPARATUS Filed May 20, 1936 s Sheets-Sheet s FIE-3 '7 INVENTOR. [mar 1.5/0/4/0 A T.TORNEYS.

Patented Mar. 7, 1939 UNITED STATES PATENT OFFICE ELECTRON RELAY APPARATUS Baxley, insane Application May 20, 1936, Serial No. 80,685

3 Claims.

This invention relates generally to electrical systems or apparatus making use of electron relays or thermionic tubes. It can be employed to advantage for the generation of electrical oscillations, and also for the amplification of the same, particularly in the field of ultra-radio frequencies, as for example wave lengths from 2 to 30 meters.

It is an object of the invention to provide apparatus of the above character which will operate at relatively high efliciency for electron relays or thermionic tubes of a given size and rating.

Another object of the invention is to provide 15 apparatus which will operate on ultra-radio frequencies, with a minimum amount of oscillatory energy being diverted in the form of harmonic or parasitic frequencies.

Other objects of the invention can be outlined 20 as followsz-To enable maintenance of a desired frequency of operation, without the use of a crystal control, and relatively independent of load variations; to facilitate a shift in the frequency of operation over a relatively wide range of wave 25 lengths, at the will of the operator; to afford a type of mutual inductive coupling between control and anode circuits, which will make for stable and eificient operation, with a minimum amount of heating of the coupler elements, and

30 to minimize direct radiation without the use of elaborate shielding means.

Further objects of the invention will appear from the following description in which certain embodiments of the invention have been set forth 35 in detail in conjunction with the accompanying drawings.

Referring to the drawings:

Fig. 1 is a circuit diagram, illustrating apparatus incorporating the present invention, and

40 for the purpose of generating high frequency oscillations.

Fig. 2 is a circuit diagram, similar to Fig. l, but showing a modification, in which the anodes are cross connected in place of cross connecting the control elements as in Fig. 1.

Fig. 3 is a circuit diagram illustrating my invention applied for the purpose of amplifying high frequency oscillations.

50 Fig. 4 is a circuit diagram illustrating a modification of the oscillation generator illustrated in Figs. 1 and 2, in which reactance means is utilized to neutralize direct capacitance between the coupling elements.

55 Fig. 5 is a circuit diagram illustrating a further modification, in which a single thermionic tube is utilized, in place of two tubes.

Fig. 6 is a circuit diagram illustrating another modification, in which a single thermionic tube, having only one control element and one anode, is substituted in place of two tubes.

Fig. '7 is a circuit diagram illustrating a modified form of coupling means for mutually inductively coupling the control and anode circuits.

Fig. 8 is a circuit diagram showing another modification in which excitation of the control element can be adjusted, and in which the inductance-capacitance ratio of the tuning circuit can be varied.

Fig. 9 is a circuit diagram showing a modification with respect to the coupling inductances, in which the inductances conform to a toroid.

Figs. 10 to 13 are cross-sectional details, showing various types of conductors for use with the present invention.

Fig. 14 is a detail in perspective showing a further modified arrangement of coupling conductors.

Referring first to Fig. 1 the oscillation generator illustrated includes a pair of electron relays or thermionic tubes Illa. and IE1). Each relay is provided with the usual anode or plate II, grid or control element I2, and cathode or electron emission means I3. The cathodes I3 can be supplied with heating current from a common supply circuit I4, and can be symmetrically connected to the ground I6. Control and anode circuits are connected to the tubes Illa and I 0b, and these circuits are mutually inductively coupled together for feed back of energy, as required for 5 the generation of oscillations.

The mutual inductive coupling consists of two conductors I1 and I8. Conductor I! is illustrated as being tubular in form, while conductor I8 is concentric thereto, that is, it extends coaxially of the tube IT. The inductances provided by these conductors I1 and I8 are symmetrically divided as will be presently explained, and the terminals of these conductors are connected in push-pull relationship to the electron relays Illa and IOb. Thus wire I911. represents a connection between one terminal of the conductor I1, and the control element of the tube Illa. Wire I917 represents an electrical connection between the other terminal of conductor I1, and the control element of tube Illb. Wire 2Ia represents an electrical connection between one terminal of conductor I8, and the anode of tube Illa, while wire Zlb connects the other terminal of conductor I8, with the anode of tube I012.

Cross-electrical connections for the control elements makes possible application of controlling potentials in proper phase relationship, for generation of oscillations.

Reactive tuning means is shown shunted directly across the conductor IT. The tuning means in this instance is in the form of a variable condenser 22, preferably of the type having an intermediate rotor shaft, which can be connected to ground 23.

Conductors l1 and I8 have adjacent electrical midpoints 24 and 25. Point 24 is connected to a suitable means for biasing the control elements l2, as for example a biasing resistor 26. Point 25 is connected to asource of anode or B-battery potential, as represented by Wire 21. This wire extends through an opening in the tubular conductor IT. The negative side of the source of B-battery potential is connected to ground, in order to complete electrical connections to the cathodes of the tubes lfla and 1012.

A load has been represented by the antenna 28 and counterpoise 29. It will be noted that this load has been shown tapped in upon the conductor H, at points symmetrical with respect to the mid-point 24. It will be evident that the nature of the load may vary, as for example in place of the antenna and counterpoise, I may utilize applicators such as are employed in high frequency therapeutic machines.

The apparatus described above will function as an eflicient generator of high frequency oscillations. By varying the setting of condenser 22 the frequency of oscillation generators can be varied over relatively wide limits, as for example from 10 to 20 meters. For thermionic tubes of a given standard rating, the capacity of the oscillation generator in terms of wattage output, is relatively high, compared to oscillation generators such as have been used in the past.

It is further characteristic of the oscillation generator described, that generation of harmonic frequencies, and parasitic frequencies is reduced to a minimum. Thus all of the oscillator ener y generated is concentrated upon a single frequency. Another desirable feature is that a high degree of stability is afforded, with respect to the frequency of operation. In the past, short wave oscillation generators have been prone to shift with respect to frequency, thus necessitating the use of a crystal control for maintaining the frequency constant. No crystal control or like stabilizing means is required in conjunction with my apparatus, because of the inherent stability afforded.

It is desirable to apply the tuning condenser to the coupling conductor for the control circuit, because such an arrangement makes possible the use of a small sized low loss condenser, whereas tuning of the anode circuit would require the use of a larger sized condenser possessing greater losses and inherent inductance. Therefore such an arrangement promotes efficient generation of higher frequency oscillations for a given size of thermionic tubes, in addition to enabling a greater tuning range, and the use of higher anode potentials at high frequencies without undue condenser losses. 7

The oscillator of Fig. 2 differs from that of Fig. 1, mainly in that the connections to the anodes H are crossed, in place of crossing the connections to the control 12. Thus wires 3la and 3H) represent cross connections between the terminals of connector !8, and the anodes H. Wires 32a and 32b represent direct connections between the terminals of the tubular conductor [1, and the control elements I2. Likewise in this instance the load has been coupled to the conductor II, by means of a coil 33, which is wrapped around the conductor i1, and by means of which the transfer of oscillator energy is mainly by capacitative relationship. The arrangement of Fig. 2, with electrical connections to'the anodes being crossed, will operate satisfactorily, although cross connections to the control elements as illustrated in Fig. 1, is preferred. Likewise with a loose coupling to the load such as described, load variations, such for example .as may be encountered with the apparatus which is being nals of conductor l8, and the anodes H of the tubes iiia and Iilb respectively. Likewise direct connections 35a and 3% are established between the terminals of conductor I! and the control elements ii. In order to nullify feed back coupling between the anode and control circuit, condensers 353 and 3? are provided. Condenser 3G is shown connected between the anode H of the tube 66a, and the grid l2 of tube lfib. Condenser 37 is connected between the control element 52 of tube Mia, and the anode H of tube Illb. These condensers are adjusted to nullify feed back coupling between the control and anode circuits, thus suppressing generation of oscillations, and permitting the apparatus to function as an amplifier. A source of high frequency oscillations to be amplified, represented by the device 38, can be impressed'across the control circuit, through the condensers 39. In this instance the load may be coupled in the same manners as illustrated in Figs. 1 and 2, or an inductive coupling can be aiiorded by coil 40, which has its axis extending in the same general direction as the axis of conductors H and 28.

In the oscillation generators of Figs. 1 and 2, the capacitance betweenthe anode and control element of each electron relay, tends to minimize the effective direct capacitance between the conductors I? and 18. Fig. 4 illustrates a modification in which the direct effective capacitance between conductors H and I8, is virtually entirely neutralized. This is accomplished by the use of condensers 41a and *dlb, Which are shunted across the respective anode and control elements of the tubes Mia and Jilb. By properly adjusting the values of condensers Ma and Mb, depending upon the physical proportioning of conductors I1 and I8, and upon the characteristics of the electron relays employed, a critical setting can be obtained wherein the direct effective capacitance between conductors i'iand i8 is substantially entirely neutralized. The principal advantage derived from this arrangement is that losses which might otherwise be involved due to capacitative relationship between conductors IT and l8,'are reduced to a minimum. Likewise, heating of the conductors I7 and i8, which is known to be objectionable in that it tends to shift the frequency of operation, is minimized.

In place of using separate electron relays or thermionic tubes, itis possible to use a single tube as illustrated in Fig. 5. In this instance a single tube H} is provided with two anodes I la and llb to control elements I 2a and l2b. Indirectly heated cathodes 42a and 42b are also shown. The connections to the anode and control elements can be virtually the same as illustrated in Fig. 4.

Where one may be satisfied with a reduced capacity, it is possible to use a single electron relay having only one anode and one cathode, as illustrated in Fig. 6. The anode I I of the tube Illa is connected by wire Zia to the one terminal of conductor I8. The control element I2 is connected by a wire |9a, to the remote terminal of conductor ll. The other terminal of conductor I8 is connected to one side of a condenser 43, the other side of which connects to the remote terminal of conductor H, by wire l9b Condenser 43 should be adjusted to match the capacitance between anode II and control element l2, plus the capacitance of condenser 4|a. It is apparent that an oscillation generator of this character will have reduced output, but it will have many of the advantages of the full pushpull types of oscillation generators previously described, and for many purposes it will sufiice.

Figs. 1 to 6 and 8 diagrammatically illustrate the conductors I? and I8, as constituting one-half turn of a coil. It is evident that the conductors can be extended to form one or more convolutions, or for extremely short waves, they may be substantially linear.

Fig. 7 illustrates an oscillation generator, particularly suitable for wave lengths near the upper end of the range indicated, as for example from 2-0 to 30 meters. In this instance the outer conductor 44 is helicoidally coiled, and is substantially shorter than the internal conductor 46. The load is coupled to the conductors 44 and 46 by means of a coil 41, which extends substantially axially of the helicoid to which conductors 44 and 46 are formed, and which is of relatively small diameter. It has been found desirable in this connection to have coil 41 wound in an opposite direction to that of conductors 44 and 46, whereby the transfer of energy is mainly by capacitance, rather than by mutual inductive coupling. The remainder of the apparatus is substantially the same as that described with respect to Fig. 4. Use of a shorter conductor 44, in comparison with the length of conductor 46, prevents any tendency towards over-excitation of the electron relays llia and H117, and thus minimizes any tendency towards generation of harmonic or parasitic frequencies, which may result from overexcitation.

The arrangement illustrated in Fig. 8 can also be utilized to secure an optimum grid excitation for any given frequency of operation. In this case the control elements, in place of being connected to the terminals of conductor H, are connected to adjustable taps. Likewise the terminals of the tuning condenser 22, can be connected to variable taps, in place of being connected directly to the terminals of the conductor By this arrangement excitation of the control elements, and also the ratio between inductance and tuning capacitance, can be adjusted to make possible a broader range of tuning, with optimum operation for a given wave length of operation. In most instances it will be found that the dead end effect which may be produced, for the end portions of conductor IT, has little if any detrimental efiect upon the apparatus.

The modifications of Figs. 1 to 8 inclusive, are characterized by the fact that the inductive coupling conductor in the control circuit, shields the associated coupling conductor in the anode circuit. Thus changes in the inductance of the anode circuit due to heating or changes in tube capacitance, is not primarily transferred to the load circuit, because the load circuit is influenced primarily by the tuned control circuit.

Fig. 9 illustrates another form of oscillation generator, utilizing a modified form of mutual inductive coupling. In this case the coupling is formed by conductor wound in the form of a toroid. Wound in close parallel relationship to conductor 5|, there is another conductor 52. The terminals of conductor 5| are cross-connected to the anodes of the relays Illa and lllb, while the terminals of conductor 52 are connected to the control elements. The electrical mid-point of the inductance formed by conductor 5|, is shown connected to the B-battery lead 53, while the midpoint of conductor 52 is connected to the biasing resistor 54. A load coupling can be provided by another conductor 56, extending axially of the toroid formed by conductors 5| and 52. Condensers 4m and Nb, corresponding to the condensers similarly designated in Fig. 4, serve to minimize direct effective capacitance between the conductors 5| and 52. A toroidal type of coupling such as described reduces direct radiation from the conductors 5| and 52, to a minimum.

In connection with the modifications described Figs. 1 to 8 inclusive, it has been stated that the outer conductor forming a part of the mutual inductive coupling between the anode and control circuits, can be in the form of a tube, with the inner conductor extending axially of the same. Such an arrangement has been illustrated in cross-section in Fig. 10. It is of course evident that suitable insulation can be interposed between these conductors in order to maintain a desired spaced relationship, and to prevent shortcircuiting. It is also possible to utilize a form such as shown in Fig. 11, in which the outer conductor 6| is in the form of an oval or rectangular tube, while the inner conductor 62 is in the form of a fiat strip or ribbon. A further possible arrangement is shown in Fig. 12 in which the outer conductor 53 has been bent from a flat strip to nearly entirely embrace the inner strip or ribbon conductor 64. Fig. 13 represents a further possibility, in which the outer conductor 66 has been bent from sheet metal to substantially entirely embrace the inner ribbon-like conductor 61. Fig. 14 is a compromise arrangement, which has been adapted in certain instances with good results, particularly for wave lengths near the upper end of the range indicated. In this case the conductors B8 and 69 are in the form of flat ribbons, wound in relatively close juxtaposition. The composite coil so formed can be helicoidally shaped, or shaped in the form of a toroid as indicated in Fig. 9. It will be evident that the coaxial relationships shown in Figs. to 13 have some advantages over the compromise arrangement of Fig. 14, particularly for the lower Wave lengths.

This application is a continuation in part of the subject matter disclosed in my co-pending application, Serial No. 745,248, filed September 24, 1934.

I claim:

1. In high frequency electrical apparatus, electron relay means including at least two anodes, two control elements, an electron emission means, and means forming mutually inductively coupled control and anode circuits for said relay means, said last means comprising a pair of conductors coiled in relatively close coextensive relationship and shaped to conform to a toroid, a set of lead connections between the terminals of one conductor and said anodes, another set of lead connections between the terminals of the other conductor and said control elements, one set of said leads being crossed, an electrical connection from a source of anode potential to the electrical midpointof said one conductor, the other side of said source of anode potential being electrically connected to the electron emission means, an electrical connection from a source of biasing potential to the electrical mid-point of said other conductor, and an electrical connection between the said last named source of biasing potential and said electron emission means.

2. In high frequency electrical apparatus, electron relay means including at least two anodes, two control elements, an electron emission means, and means forming mutually inductively coupled control and anode circuits for said relay means, said last means comprising a pair of conductors coiled in relatively close coextensive relationship and shaped to conform to a toroid, a set of lead connections between the terminals of one conductor and said anodes, another set of lead connections between the terminals of the other conductor and said control elements, one set of said leads being crossed, an electrical connection from a source of anode potential to the electrical mid-point of said one conductor, the other side of said source of anode potential being electrically connected to the electron emission means, an electrical connection from a source of biasing potential to the electrical mid-point of said other conductor, and an electrical connection between the said last named source of biasing potential and said electron emission means and reactance means serving to minimize direct capacitance between said conductors.

3. In high frequency electrical apparatus, electron relay means including at least two anodes, two control elements, an electron emission means, and. means forming mutualy inductively coupled control and anode circuits for said relay means, said last means comprising a pair of conductors coiled in relatively close coextensive relationship and shaped to conform to a toroid, a set of leads serving to connect between the terminals of one conductor and said anodes, another set of leads serving to connect between the terminals of the other conductor and said control elements, one set of said leads being electrically crossed, an electrical connection from a source of anode potential to the electrical mid-point of said one conductor, the other side of said source of anode potential being electrically connected to the electron emission means, an electrical connection from a source of iasing potential to the electrical mid-point of said other conductor, and an electrical connection between the said last named source of biasing potential and said electron emission means, a conductor extending coincident with the curved axis of the toroid, and a load connected to the terminals of said last named conductor.

ELMER, L; BROWN. 

